Avoid a double delete of BrowserUI on shutdown.

mandoline/ui/browser/browser.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mandoline/ui/browser/browser.h"
 
 #include "base/command_line.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/view_manager/public/cpp/view.h"
 #include "components/view_manager/public/cpp/view_manager_init.h"
@@ skipping 22 matching lines @@
 Browser::Browser()
     : root_(nullptr),
       content_(nullptr),
       omnibox_(nullptr),
       navigator_host_(this),
       ui_(nullptr) {
   exposed_services_impl_.AddService<mojo::NavigatorHost>(this);
 }
 
 Browser::~Browser() {
+  // Destruct ui_ manually while |this| is alive and reset the pointer first.
+  // This is to avoid a double delete when OnViewManagerDisconnected gets
+  // called.
+  delete ui_.release();
 }
 
 void Browser::ReplaceContentWithURL(const mojo::String& url) {
   Embed(url, nullptr, nullptr);
 }
 
 void Browser::Initialize(mojo::ApplicationImpl* app) {
   view_manager_init_.reset(new mojo::ViewManagerInit(app, this, this));
 
   ui_.reset(BrowserUI::Create(this, app));
@@ skipping 117 matching lines @@
   if (!omnibox_) {
     omnibox_ = root_->view_manager()->CreateView();
     root_->AddChild(omnibox_);
     omnibox_->SetVisible(true);
     omnibox_->SetBounds(root_->bounds());
   }
   omnibox_->Embed(url, services.Pass(), exposed_services.Pass());
 }
 
 }  // namespace mandoline